Interlocking apparatus



Dec. 14 1926.

F. FIX

INTERLOGKING APPARATUS Filed Dec. 16. 1920 3 Sheets-Sheet 5 INVENTOR fiank Fix, B

' ATTORNEY Patented Dec. id, 192.

FRANK FIX, OF NORTH'IRWIH, PENNSYLVAZQ'IA, TO VJESTINGHOUSE ELEG- TRIG & MANUFACTURING COMPANK,

A GOB?OP-ATGH F EENNSYLVANIA.

INTEELGCKENG ATPPABATUS.

Application filed December 16, rest. seen so. 4.31.957.

.Lly invention relates to mechanical interlocking devices that are adapted to insure the proper relative movements 01": a plurality of levers. such as are employed in connection with the operation of electric switches.

My invention is designed especially for use in connection with electric motors that require a relatively low voltage when being started and a higer voltage to bring them up to. and to maintain them at, their normal running speeds.

One object of my invention is to provide a construction wherein the switch that controls the low-voltage circuit must be moved to starting position before the switch that controls the high-voltage circuit can be closed and wherein each switch is held against closing movement while the other switch is in closed position.

Another object is to provide means wherebv the switch that controls the high-voltage circuit cannot be moved to closed position except within a limited time after the lowvoltage circuit has been opened.

Various types of apparatus have been designed to automatically provide for the proper sequence of operation, as between a starting switch and arunning. or high-voltage, switch, but difficulty has been experienced in designing a structure wherein provision is made to insure the closing oi the running switch before the motor has lost the momentum set up therein through the operation of the starting switch.

I provide a construct-ion wherein the running switch must be closed, it at all, at substantially the instant that the starting switch leaves its closed. position.

In. the accompanying drawings:

Figure 1 is an end elevational view of my device as applied to apair of controlling levers, such as are used on an ordinary circuit breaker;

' Fig. 2 is a side elevational view of the same; Figs. 3 and 4 are side elevational views showing the position occupied by certain or" the parts at different stages of their operation;

' Fig. 5 1s an enlarged detail view of my locking member in a position opposite to that illustrated in Fig. 1;

Fig. 6 is a view, in end elevation. of a modified form of locking apparatus. and

Figs. 7 and Sale a side elevation and a plan view, respectively, of such modified form.

My device is shown as applied to the lowvoltage and the high-voltage operating levers of an ordinary circuit breaker; A handle 10 is provided for controlling a lowvoltage switch (not shown) and a handle 11 is provided torcontrolling the high-volt age switch or circuit breaker. These handles are provided with levers 12 and 13, respectively, that are pivoted at 14. to a bracket 15 that is secured to a panel 16. i

A locking member 17, which is provided with hook portions 18 and 19, is also pivoted on the bracket 15,,at. 20. This locking member is normally held in the position indicatedin Fig. 1. by" means of a compression spring 21 which seats on a shelf-like extension 22 of the bracket 15. The'locking member 17 is provided with an arm 23 adapted to be engaged by a latch member 2% that is pivoted at 25 to tlie'starti'ngswitch lever 12. 7

The locking member 1'? is so mounted that, when the hook 18 is moved out of the path of travel of the lever 13, the hook 19 will thereby be moved into the path of travel of the lever 12 to prevent both of said levers. from occupying their upper, or closed, positions at the same time.

In order to move the locking member 17 out of engagement with the running-switch lever 13, the starting-switch lever 12 must be returned from its upper, or closed, position, as indicated in Figs. 1 and 2, to its open or lower'position. as indicated in Fig. 5. This movement of the starting-switch lever causes the latch member 24.- to engage the arm 23 and thereby move the locking member 17, against the spring 21 into the position shown in Fig. 5. In this position, the runnin -switch lever 13 may be freely advanced toclosedrposition, and the starting-switch lever is locked against movement to closed position. i

' The latch member 24: isprovided with a weighted extension 26, an engaging portion 27, and cam portion 28. Asthe handle 10 is raised to open the starting switch, the lever 12 descends, carrying with it the latch membQT'241. During this movement, the cam portion 28 engages the arm'23 of the locking member 1'7 which causes the latch member 24. to be thrown to substantially the position aof ill)

As the lever 12 descends past the position shown in Fig. 3, the latch member 241 moves around its pivot 25, until. approximately the instant that the lever 12 reaches its further most position. It is to be observed that the pivot 25 moves along the arc of a circle having its center at the pivot 1 1 while the arm 23 moves ina vertical plane about the pivot 20 whereb the an ular relation between the pivot 25 and the arm 23 is constantly changing. The pivot point 25 will in its lower po sition occupy a position at an angle to the arm 23 such that the engaging member 27 will slip from the arm 23 and leave the looking member 17 free to be returned to the position indicated in Fig. 1, providing the running-switch lever 13 has not, in the meantime, been raised to close the high-voltage or running switch.

The arrangement of the latch member 2 1 is such that the portion 27 thereof engages.

the arm 23 at substantially the instant that the starting-switch lever 12 has opened the low-voltage circuit, and between that period and the time when such lever passes the position shownin Fig. 5, the running-switch lever 13 must be moved, if it is to be moved at'all, as the locking member 17 is'disen gaged by the latch member only at substantially the position shown in Fig. 5.

As the lever 12 descends, the cam portion 28 of the latch member 2d is thrown to the position indicated in Fig. 3, as it passes the arm 23. The weighted portion 26. is provided in order to regulate the range of pivotal movement of-the latch member and to normally maintain the latch member inthe position illustrated in Fig. 4, The utility of the above described form of latch member resides in the fact that the startingswitch lever must'be moved downwardly at a reasonably high speed, in order to make engagement betweenv the member 27 and the arm 23. If the lever is moved slowly, as would be the case in accidental movement thereof, the weight 26 would cause the latch member 24 to assume the position shown in Fig. 4 before the portion 27 came into engagement with the arm 23,. and would thereby prevent engagement of the member 27 and the arm 23.

From the foregoing, it will be seen that, in order to release the running-switch lever 13,

, the starting-switch lever must be moved to open position quickly, and that the runningswitch lever is unlocked only for a portion of the period during which the startingswitchlever is moving to open position.

This requires that the -movement of the starting-switch lever and the closing movement of the running-switch lever must be ing member occupies the position, indicated in the position shownsin Fig. 5, it will, of course, be automatically locked at the com pletion of the downward. travel of the lever 12, and it cannot-be advanced until the lever :12 has again been moved to closed position and retracted.

The running-switch lever 13 is provided with a boss 29 that slides along the face of the hook 18, as the lever is moved upwardly,

and holds the locking member 17 in the-position illustrated in Fig. 5. When the running-switch lever is returned to open position, the spring 21 causes the locking member 17 to again assume the position shown in Fig. 1, wherein the running-switchlever 13 is locked against closing movement, and the path of travel. of the starting-switchlever 12 is unobstructed.

In the form of locking device illustrated in Figs. 6, 7 and 8, the latch member 24 ops crates in the manner above described, and the starting-switch and running-switch levers are controlled in the same'manner.

In this form of device, the locking element consists of two members 30 and 31 pivoted at 32 to the bracket 15 and adapted to extend into the path of travel of the levers 12 and 13. Thelocking member 31 has :1 lug 33 formed thereon in position toengage the upper edge of the locking member 30 and there limit'th'e pivotal movement of such member 31, with respect to the member 30. v 1 g The latch member 34 is pivoted: at 35 to IOU the bracket 15 and extends across the top edge of the locking member 30 to prevent upward movement thereof. The latch member 34 has an extension 36 lying in. the path of a pivoted arm 37 that is adapted to be move upwardly about. the pivot 32, and. out

of the path of'the ruimingswitch lever 13..

As the running-switch lever moves up, it

ill

carries the lockin member with it, and this locking mem er, through the lug 33, moves the locking member 31 down against the upper edge of the starting-switch lever to prevent upward movement thereof while the runningswitch lever is in closed position.

After the running-switch lever has re turned to lower position, as indicated in Fig. 6, the starting-switch lever 12 may be moved upwardly to closed position, and this movement will again place the locking device in position to lock the running-switch lever against closing movement.

Each of the levers 12 and 13, in the modification illustrated in Figs. 6, 7 and 8, has a hook 40 formed thereon, in the manner shown more clearly in Fig. 7. This hook assists in maintaining each of the locking members 30 and 31 in proper position with respect to its associated lever. As the levers descend, the hooks carry the locking men1- bers along and ensure against such members sticking in their upper positions.

Various modifications may be made in the device without departing from the spirit of the invention, as defined in the accompanying claims. i

I claim as my invention 1. In combination, in an interlock mechanism, a pair of levers, a locking member adapted to normally look one of said levers in retracted position, a latch carried by the other lever and adapted to engage the looking member during a portion of the travel of said lever to retracted position to disengage it from the first-named lever, and means whereby the movement of the first-mentioned lever to advanced position causes the locking member to engage the other lever and hold it in retracted position.

2. In combination, in an interlock mechanism, a pair of levers, a locking member adapted to normally lock one of said levers in retracted position, a latch carried by the other lever and adapted to engage the locking member during a portion of the travel of said lever to retracted posltion to dlsengage the locking member from the first named lever, means whereby the movement or" the first-mentloned lever to advanced po.

sition causes the locking member to engage the other lever and hold it in retracted position, and means whereby the return of the firstenamed lever to retracted position permits the locking member to assume its 1101'? mal position. I i

3. In combination, in an interlock mechanism, a pair oflevers, a lockingmember adapted to normally look one of said levers in retracted posltion, and a latch carried by the other lever in position to engage the locking member during a portion of the travel of said lever toretracted position to disengage the locking member from the firstnamed lever.

4. In combination, in an interlock mechaism, a. starting-switch lever, a runningswitch lever, means for normally locking the running-switch lever in retracted position, and a latch carried by the starting-switch lever in position to engage the locking means at substantially the instant that said lever leaves its closed position and adapted to be disengaged therefrom before the lever completes its movement to open position.

5. In combination, in an interlock mechanism, a starting-switch lever and a running-- switch lever,means for normally locking the running-switch lever in retracted position, means actuated by the starting-switch lever during a portion of its movement to retracted position for temporarily releasing the running-switch lever, and means whereby the starting-switch lever is locked in retracted position while therunning-switch lever-is in advanced position. I

In testimony. whereof, I have hereunto subscribed my name this 22nd day of November, 1920.

FRANK FIX. 

